Calunium power adaptors
Power adaptors to operate the microcontroller at 3.3V (top) or 5V (bottom). In both cases the 3.3V regulator and polyfuse on Calunium is omitted. By inserting one of the adaptors onto the auxillary power connector the voltage at which the microcontroller operates is easily selected. Power is supplied via the USB or FTDI connectors.
I built these so that I could power the board via USB for development and then fit a shield containing a boost regulator for battery powered operation. The combination of the right-angled connector on the stripboard and the polarized Molex connector on the PCB prevents the adaptor from being inserted in reverse (but not misaligned).